I’d recommend getting actual barber clippers for this, and not the cheap type that you get from the drug store. You don’t have to spend a lot either. Either some Oster Fast Feeds or Whal Magic Clips can be purchased for around $70, and will be WAY better than anything at the drug store, for a nice even length trim of a beard.

Wahl Professional 5-Star Magic Clip #8451 – Great for Barbers and Stylists – Precision Fade Clipper with Zero Overlap Adjustable Blades, Variable Taper & Texture Settings (with Clipper Oil) https://www.amazon.com/dp/B07MZ7BRMR/ref=cm_sw_r_cp_api_glt_fabc_ZJ77Y1WW197ZVFQTBEQY

Oster Professional 76023-510 Fast Feed Clipper with Adjustable Blade + 8 piece comb set https://www.amazon.com/dp/B0072M7MAU/ref=cm_sw_r_cp_api_glt_fabc_084KJJ6BMSM6X83SMAPH